What are some cool place ideas for Roblox

Make a place no one has made before. Some cool ones would be a fight between space ships.
Another cool thing to do is to try and create a real non Roblox game and make it as close to the real game as you can. Call of Duty is way over used in this category so I would recommend using a game such as Grand Theft Auto or some game that is either less used or not very true to the ordinal game.